1. Field of the Invention
The present invention relates to an organic dye, and in particular relates to an organic dye used in dye-sensitized solar cells (DSSCs).
2. Description of the Related Art
Development in the solar cell industry is driven by global environmental concerns and rising raw material prices. Among the various solar cells developed, dye-sensitized solar cell (DSSC) is advantageous as it can be fabricated with relatively lower costs due to its simpler fabrication process and suitability for large area fabrication.
There are two kinds of dye used in DSSCs, one is large organic molecules (such as coumarin, cyanine), the other is ruthenium (Ru) metal complexes. The performances of DSSCs based on large organic molecules are usually insufficient. On the other hand, ruthenium (Ru) metal complexes have better performance, but its molar absorption coefficient at short wavelength regions (about 350 nm-500 nm) is lower than that of large organic molecules.
Thus, there is a need to develop an organic dye which has high molar absorption coefficient in short wavelength regions. If such an organic dye and ruthenium (Ru) metal complexes are used together, the photoelectric conversion efficiency of DSSC should be improved.